Dataset Information

Dopaminergic subset specification as a model for molecular mechanisms of neural vulnerability in Parkinson's Disease

ABSTRACT: Mesodiencephalic dopaminergic (mdDA) neurons critically regulate locomotory behavior and emotion, and dysfunction is associated with psychiatric and neurodegenerative diseases, including Parkinson's Disease (PD). A pathological hallmark of PD is the specific degeneration of Substantia Nigra (SN) neurons, whereas Ventral Tegmental Area (VTA) neurons are relatively unaffected. Differential molecular programming of the developing SN versus VTA may underly this specific vulnerability, and indeed molecularly distinct mdDA subsets have been identified during development. Driven by the hypothesis that the molecular signature of the SN and VTA originates from differential developmental programming and position along the rostral/caudal axis, we performed genome-wide expression profiling of FACS-purified rostral versus caudal mdDA neurons. Here, we present the distinct transcriptomes of these mdDA subsets and demonstrate how, on a genome-wide scale: 1) transcription factor regulation relates to developmental position, 2) rostral and caudal mdDA neurons differ in their functional genome, 3) the molecular signature of rostral versus caudal mdDA neurons relates to the SN versus VTA molecular profile in adult mice and human and 4) human homologues of rostrally enriched genes are mostly downregulated in the SN of PD patients. Our analyses substantiate the relationship of developmental positions with the SN versus VTA distinction in adult, and suggest cross-species conservation of molecular programs. Driven by these observations, we present 69 target genes that are rostral enriched and downregulated in PD, and thus provide new leads for the investigation of both the complex coding of developing mdDA subsets and and the molecular mechanisms underlying subset-specific vulnerability in PD.

ORGANISM(S): Mus musculus

PROVIDER: GSE57424 | GEO | 2016/12/31

SECONDARY ACCESSION(S): PRJNA246426

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Implications for neuroprotection in Parkinson's disease Parkinson’s disease and its characteristic symptoms are thought to arise from the progressive degeneration of specific midbrain dopamine (DA) neurons. In humans, DA neurons of the substantia nigra (SN) and their projections to the striatum show selective vulnerability, while neighboring DA neurons of the ventral tegmental area (VTA) are relatively spared from degeneration. This pattern of cell loss is mimicked in humans, primates, and certain rodents by the neurotoxin MPTP. In this study, we aimed to test the hypothesis that there are factors in the VTA that are potentially neuroprotective against MPTP and that these factors change over time. We have found a differential transcriptional response within the cells of the SN and VTA to sustained exposure to a low dose of MPTP. Specifically, the VTA has increased expression of 148 genes as an early response to MPTP and 113 genes as a late response to MPTP toxicity. This response encompasses many areas of cellular function, including protein regulation (Phf6) and ion/metal regulation (PANK2, Car4). Notably, these responses were largely absent from the cells of the SN. Our data show a clear dynamic response in maintaining the homeostasis and viability of the neurons in the VTA that is lacking in the SN after neurotoxin challenge. We used microarrays to analyze the differential response of the substantia nigra (SN) and ventral tegmental area (VTA) to a chronic low dose of the neurotoxin MPTP. Transgenic hTH-GFP mice were treated with MPTP (4mg/kg) for either 2 or 10 days. Control mice were given an equal volume of saline for 10 days. Dopamine neurons from the substantia nigra and ventral tegmental areas of control and MPTP treated animals were laser captured. The RNA was isolated and processed for microarray hybridization. Each group had three biological replicates, for a total of 18 samples. Three each in the following: Control SN, Control VTA, 2 day MPTP SN, 2 day MPTP VTA, 10 day MPTP SN, 10 day MPTP VTA. Samples were log2 transformed and RMA normalized using Agilent Genespring 10.0 GX.

Dataset Information

Dopaminergic subset specification as a model for molecular mechanisms of neural vulnerability in Parkinson's Disease

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure